wp-calypso/client/lib/gsuite/can-domain-add-gsuite.js

/**
 * Determines whether G Suite is allowed for the specified domain.
 * @param {string} domainName - domain name
 * @returns {boolean} - true if G Suite is allowed, false otherwise
 */
export function canDomainAddGSuite( domainName ) {
	if ( domainName.endsWith( '.wpcomstaging.com' ) ) {
		return false;
	}

	return true;
}